There already exist numerous varieties of weather strip for sealing the glass or pane of a car window, such stripe being fixed around the window frame in a vehicle door and being referred to herein as "slides" when they line the top and sides of an opening suitable for being opened or closed by a moving retractable sheet of glass, and as "bottom wiper seals" or "wiper seals" when they are provided along the bottom edge of such an opening. Although wiper seals, and indeed slides, are required to provide adequate sealing against water, and also to contribute to providing sound insulation, they also serve to provide outer functions. Thus, slides also act as guide members and as protection members, unlike wiper seals, whereas wiper seals contribute to the appearance of the vehicle and are required also to project as little as possible from the opening in the door.
In order to satisfy this condition, car manufacturers desire that the sealing lip, i.e. the operative portion per se of the wiper seal should extend as closely as possible perpendicularly to the moving glass.
The solutions provided to this problem in the prior art have given rise to weather strips which are available on the market and which include one or two sealing lips made of natural or synthetic rubber carried on a stub optionally including reinforcement, with the lip(s) bearing and deforming against the moving surface.
However, since having such a lip bearing against the glass tends to slow down the sliding of the glass, proposals have been made to cover the surface of the lip which comes into contact with the glass in a layer having good sliding properties.
To this end, the sealing lips of some retractable window wiper seals are covered with a layer of flock comprising textile strands or fibers constituting a covering which is somewhat analogous to velvet. Although sliding properties are improved thereby, lips treated in this way nevertheless loose these qualities fairly rapidly, in particular because of their relatively rapid rate of wear. These lips have therefore been replaced by lips coated with a smooth sliding coating made of polyolefin, polytetrafluoroethylen, or other material (generally a synthetic material) which withstands friction wear wall and which provides good sealing against both air and water, while nevertheless having good sliding properties. Unfortunately, this solution is not entirely satisfactorily since it increases the danger of the glass being scratched by dust, which risk is further increased due to the transverse displacement of the glass while it is being raised or lowered because of the somewhat bulging shape given to the doors and windows in many recent models.
Consequently, an object of the invention is to provide a wiper seal for wiping the bottom of a moving motor vehicle window glass, which viper seal is simple and cheap to make while nevertheless obtaining good sealing against water and good sound isolation while avoiding damaging the glass or window with which it co-operates.